1. Field of the Invention
The present invention relates to an information recording and reproducing apparatus for recording information on a recording medium and/or reproducing the information recorded on the recording medium.
2. Related Background Art
An information recording and reproducing apparatus includes a magnetic type and an optical type. Of those, the optical type has been recently attracting notice. An apparatus for recording/reproducing information by using a light beam uses a disk-shaped rotary recording medium such as a CD, an optical disk (video disk) of a magneto-optical disk, and a card-shaped reciprocal recording medium such as an optical card or an optical tape. Those media are selectively used depending on the purpose. Of those, the optical card has been attracting notice because of its high portability. When the optical card is used as the information recording medium, a light beam is irradiated to the optical card and the light beam irradiation position is linearly moved and it is further moved transversely to the direction of the linear movement, that is, in a direction transverse to the information tracks on the optical card, as is known in the art.
Prior art devices of this type are shown in FIGS. 1 to 4B. FIG. 1 shows a perspective view of a first prior art device. A mount or card table 2 movably supported along an X direction by rails 1a and 1b pushes and fixes an optical card C inserted from the side by leaf springs 3a and 3b of a card pushing member 3 in a periphery of the optical card C. Feed rollers 4a and 4b for loading the optical card C into the card table 2 are rotated by a motor 6 through a drive shaft 5 to feed the optical card C. In order to feed the optical card C to an abutment 2a of the card table 2, notches 3c and 3d are formed in the card pushing member 3 so that the feed rollers 4a and 4b engage with the notches 3c and 3d. The motor 6 and the drive shaft 5 are movable vertically because a movable core 8 fixed to one end of a member 7 which is rotatable around a shaft 7a is driven by a spring 9 and a solenoid 10.
FIG. 2 shows a sectional view taken along a line VII--VII of FIG. 1. FIG. 2A shows the loading of the optical card C into the card mount 2, and FIG. 2B shows the feed rollers 4a and 4b which are the feed system off the card table 2. When the optical card C is fed to the abutment 2a of the card table 2 by the feed rollers 4a and 4b and the optical card C is positioned to the card table 2, the motor 6 stops and the feed rollers 4a and 4b move up by the solenoid 10 and move off the feed status for the optical card C. The optical card C positioned to the card table 2 moves off the feed system and makes a linear reciprocating movement with the card table 2 so that the information is recorded or reproduced.
FIG. 3 shows a second prior art device. Feed rollers 13a, 13b, 13c and 13d for loading the optical card C into a card table 12 are provided on vertically arranged parallel shafts 11a and 11b and they are arranged to face each other to hold the optical card C therein. In order to load the optical card C to an abutment 12a of the card table 12, the length of the card table 12 along the direction of movement is shorter than the longitudinal length of the optical card C and the feed rollers 13a to 13d are arranged thereat. As shown in FIG. 4A, which is a sectional view taken along a line IX--IX of FIG. 3, the optical card C is held by the feed rollers 13a to 13d and fed to the card table 12. The optical card C is loaded while it is forced by a card pushing member 14 so that it is parallel to a pushing plane 15, and when the optical card C abuts against the abutment 12 a of the card table 12, the positioning is completed. When the optical card C is positioned, the feed rollers 13a, 13b, 13c and 13d are vertically moved as shown in FIG. 4B to isolate the optical card C from the feed system. Subsequently, the recording/reproducing mode which is similar to that of the first prior art device is started.
However, in the above mechanisms which use the feed rollers, the following common disadvantages are observed. In the first prior art device, since portions of the pushing member 3 which pushes the optical card C are cut away, a warp of the optical card is not fully removed, and the optical card C swings significantly in the recording/reproducing mode to induce a recording/reproducing error of the optical head. In the second prior art device, a portion of the optical card C extends beyond the card table 12 and it poses a similar problem to that of the first prior art device. In both prior art devices, the feed rollers which feed the optical card C are so close to the card table on which the optical card C is mounted that the linear reciprocating movement is interfered with. Accordingly, it is necessary to retract the feed rollers to isolate them from the card table immediately after the positioning of the optical card C when the optical card C is received by the card table. Since the feed rollers are usually made of rubber elastic material, a variation is produced on a contact plane of the optical card C and the feed rollers by a restoring repulsive force created when the feed rollers move off the optical card C. As a result, a write position varies and sometimes the irradiation beam of the optical head may be positioned at other than a record area of the optical card C. Because of those disadvantages, it is difficult by the prior art devices to minimize an information record pit size as required by the present technology and record/reproduce information to/from the optical card which stores a large volume of information.